We use the tzatziki sauce to calm some of the heat, I as often add more curry paste than is called for in the recipe (my husband loves spicy foods). You can also purchase a jar of mango chutney and serve with the meal; that's awfully tasty as well.
Although many tzatziki sauce recipes call for mint, I don't add it to mine. However, I will often add a bit of greek seasoning mix to get a hint of mint flavor.

Ingredients

2 pounds beef round steak, cut into cubes

2 medium onions, chopped

1 28 oz can diced tomatoes

2 tbsp red curry paste

1/2 cup water

3 oz (1/2 bag) spinach leaves

2 cups plain (preferably greek) yogurt

1 medium cucumber

1 tbsp lemon juice

Rice

Instructions

Place meat in slow cooker, add onions. Combine diced tomatoes, curry paste, and water in a bowl, pour over meat and onions. Cover and cook on low 8 hours or high for 4 hours.